Ok....this is really confusing. I successfully created a small test project several months ago using the Boost Serialization library to serialize some binary data. I am now attempting to add binary serialization to a production project, and I receive a bunch of compiler warnings. I can still compile and execute the test application with no warnings or errors. I am using VS2005 with boost 1.34.1 I have included the first few compiler warnings below... 1>C:\Program Files\boost\boost_1_34_1\boost/archive/basic_binary_oprimitive.hpp(136) : warning C4267: 'argument' : conversion from 'size_t' to 'std::streamsize', possible loss of data 1> C:\Program Files\boost\boost_1_34_1\boost/archive/basic_binary_oprimitive.hpp(120) : while compiling class template member function 'void boost::archive::basic_binary_oprimitive<Archive,Elem,Tr>::save_binary(const void *,size_t)' 1> with 1> [ 1> Archive=boost::archive::binary_oarchive, 1> Elem=char, 1> Tr=std::char_traits<char> 1> ] 1> C:\Program Files\boost\boost_1_34_1\boost/archive/detail/oserializer.hpp(91) : see reference to function template instantiation 'void boost::archive::basic_binary_oprimitive<Archive,Elem,Tr>::save<T>(const T &)' being compiled 1> with 1> [ 1> Archive=boost::archive::binary_oarchive, 1> Elem=char, 1> Tr=std::char_traits<char>, 1> T=unsigned char 1> ] 1> C:\Program Files\boost\boost_1_34_1\boost/archive/detail/oserializer.hpp(244) : see reference to function template instantiation 'void boost::archive::save_access::save_primitive<Archive,T>(Archive &,const T &)' being compiled 1> with 1> [ 1> Archive=boost::archive::binary_oarchive, 1> T=unsigned char 1> ] Thanks, Dave -- Dave Nay CIVision, LLC